31.8. 2023
| Advices

How do I read the data on my tyres?

On the sidewall of each tyre, you will find some basic information that is important for making the right choice. The same information can be found in your car's technical certificate and in the label of each of our tyres. To help you understand the meaning of specific numbers and letters on the tyres, here is a sample example.
How do I read the data on my tyres?

Tyre size table


205/55R 16 85 T

205 tyre width in millimetres
55 profile height in percent of width
R marking of radial tyre construction
16 rim diameter in inches
85 load capacity index
T speed index

Tyre dimensions: explanations

For a better understanding of what the various indications on the tyre sidewall mean, see the more detailed explanations of each indication:

  • The tread width is written in millimetres. It is the maximum width of the tyre at nominal inflation pressure and nominal load. Our sample tyre is 205 mm wide.
  • The profile number expresses the ratio between the tyre width and the sidewall height expressed as a percentage. The sidewall height of our tyre is 55% of the total width of 205 mm, i.e. approximately 112.75 mm.
  • The letter R stands for radial tyre construction. Diagonal tyres are usually marked with a dash "-"
  • Rim diameter refers to a value that expresses the rim dimension in inches. One inch equals approximately 2.54 cm. In our case, the tyre is suitable for 16 inch diameter rims.
  • The load index of a tyre is a dimensionless number that corresponds to the nominal operating load in kg per tyre.
  • The speed index of a tyre is the letter corresponding to the speed category for which the tyre was designed.
  • If the tyre is marked M+S (mud+snow), it is a winter tyre or tyre suitable for off-road use.
  • Tyre energy labels (European tyre labels) for fuel consumption, wet grip and noise levels.

Where can I find the right tyre size for my car?

The permissible tyre dimensions, load index and speed index can be found in the vehicle's technical certificate. Fitting other dimensions is not permitted.

How do I enter a different tyre size on my registration certificate?

You can, of course, ask for an alternative tyre size to be added to your registration certificate.

  • You will need a type certificate or an expert opinion, which you will then need to take to the STK, where they will confirm the installation.
  • With the confirmed document, you can then go to the traffic inspector's office, where the new dimension will be entered on your licence.
  • However, please note that the outer diameter of the alternative tyre may vary by a maximum of +1.5% to -2%.

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